import java.util.TreeMap;

public class Test01 {
    public static void main(String[] args) {
        TreeMap<Student,String> tm=new TreeMap<>();
        Student s1=new Student("zhangsan",23);
        Student s2=new Student("lisi",26);
        Student s3=new Student("wangwu",25);
        tm.put(s1,"山东");
        tm.put(s2,"北京");
        tm.put(s3,"江苏");
        System.out.println(tm);
    }
}
